Traditionally pregnant diabetic women have had poor fetal outcomes and the ability of these women to breast feed has been questioned. This project proposes to determine the adequacy of human milk from diabetic mothers. Nutrient composition (lactose, glucose, galactose, total fat, total fatty acids, cholesterol, total protein, total nitrogen, calories, vitamin E, calcium, ketones), specific gravity, volume and prolactin, as well as indices of mastitis (somatic cell and microbiological analyses, sodium, potassium, chloride, conductivity and osmolality) of breast milk from insulin dependent diabetics with good and poor metabolic control will be compared to matched non-diabetic subjects. The study will consist of 40 insulin dependent diabetic mothers, 20 with good metabolic control and 20 with poor metabolic control in a 1:1 match with non-diabetic controls. Since both the diabetic women and their controls will have a high incidence of complications at delivery, these women, their milk and their infants will also be compared to comparable data from a sample of 40 low risk reference women. The relation between plasma nutrient levels and breast milk levels will also be determined and infant growth rate will be monitored. If breast milk from diabetic mothers differs in composition or volume, infant growth may be adversely affected. Determination of breast milk composition and microbiological analyses of diabetic milk may provide a means of monitoring mastitis in diabetics who are prone to infections. This research would help to determine a protocol for breast feeding by diabetic mothers.